The present invention relates generally to adaptive cruise control systems for automotive vehicles, and more particularly to an adaptive cruise control system for an automotive vehicle, which warns a driver and/or reduces a vehicle speed in advance of entry into an upcoming curve in accordance with a driving state of the vehicle.
In recent years, there have been proposed and disclosed various adaptive cruise control systems for automotive vehicles, which reduce the vehicle speed to reduce a tendency to understeer when the vehicle is traveling through a curve or a corner in a driving condition in which the vehicle lateral acceleration is larger than a threshold value. These systems prevent outside deviation or drift-off of the host vehicle from a current curved path even when the host vehicle enters a curve too fast due to driver's mistakes such as inadequate caution to the current path and wrong assessment of the current path. This enhances the stability of the vehicle to make the driver of the vehicle feel comfortable. A Published Japanese Patent Application No. H4(1992)-236699 (hereinafter referred to as “JP4-236699”) shows an adaptive cruise control system for an automotive vehicle. This system obtains information about a forward curve based on information provided by a navigation system or infrastructural equipment, in advance of entering the curve. When the vehicle speed is too large to travel through the curve, the system starts to reduce the vehicle speed in advance of the entry into the curve. A Published Japanese Patent Application No. H8(1996)-194891 shows another adaptive cruise control system for an automotive vehicle. The system controls the host vehicle in consideration of errors in information from a navigation system.